Under Covers
by elsannonymous
Summary: Home from college for the holidays, Anna gets a pleasant surprise when she visits her sister in the middle of the night to share warmth. [G!P Anna, Sleep Sex]


A furious banging against the window woke Anna with a start. She sat up, her fiery, untamed mane flying in all directions. Pushing her hair back out of her eyes, she looked around the darkened bedroom, gnawing on her lip. Another bang startled her, but she realized it was just the sound of the rushing wind smacking against the pane. Outside was a pure white nightmare, nothing visible but the blizzard as it raged on.

She shivered, realizing how cold she was, and hopped out of bed, stretching as she landed on her feet. Hastily pulling her pajamas back into order - her clothes always seemed to twist out of shape when she was sleeping - she raced out of her room and down the hall, throwing the door to her sister's bedroom open and slamming it shut behind her.

"Ughn…" A groan from the bed rang out, but Anna ignored it in favor of diving on top of the lump underneath the covers. "Oof! Anna… What are you doing," Elsa groused, pulling her comforter over her head.

"Els, it's freezing," Anna whined back, rolling to the side and taking the blanket in her hands. "I think the power's out. I can't get warm in my own bed, so I'm sleeping with you." Elsa's eyes flew open, all sleep fleeing from her, and she rolled to face Anna' grabbing for her hands.

"Wait, Anna, I'm-"

The younger woman flung the covers to the side before sidling underneath them and snuggling against her sister, her hands slipping over Elsa's waist - and connecting with the pale woman's smooth skin.

"Naked…"

The sisters froze, facing each other, cheeks glowing red, Anna's hands trembling against Elsa's sides. "Uh," Anna mumbled finally, averting her eyes from Elsa's gaze, "c-can I still sleep here? It's really cold in my room…" Elsa swallowed and nodded, watching as Anna turned onto her side, back to her older sister, and nestled into a pillow. "Night, Elsa," Anna whispered, staring at her hands. They still tingled from touching Elsa's cool flesh.

"…Night."

Laying still and quiet next to her sister - whom she assumed had fallen back asleep - Anna stared into the dark, nibbling on her lower lip and grasping at the covers. She was hyperaware of the fact that Elsa was completely nude behind her. She knew that she shouldn't be thinking of her sister, naked and prostrate on a bed next to her, but her mind raced as she remembered the feeling of Elsa's soft skin beneath her fingertips. Anna stiffened when the subject of her thoughts shifted behind her, trembling as Elsa shuffled closer and pressed her body against Anna's back. Her arm looped around Anna's waist and pulled her against Elsa's front as the blonde nuzzled Anna's neck. "E-Elsa?" Anna whispered, clutching her hands together in front of her. Her sister only sighed. "She's asleep?" Anna muttered to herself, trying not to dwell on the pressure of Elsa's naked breasts pushing against her back, the thin material of her shirt doing nothing to muffle the feeling of Elsa's nipples poking into her shoulder blades.

Shit. Shit shit shit. Anna stuffed a fist in her mouth, humming a mindless tune and definitely not thinking of her sister's nipples or breasts or toned stomach or long, smooth legs or what was in between-

Anna hummed louder and more desperately, the song morphing into melodious muttering. "Antimony, arsenic, aluminum, selenium, and hydrogen and oxygen and nitrogen and rhenium," her recitation slowed, racking her brain, trying to remember what she'd been studying earlier before going to sleep, "Hmm-hmm, uhhh…" Her breath hitched when Elsa shifted again, pressing ever closer. Her hands played with the hem of Anna's shirt, barely brushing against her tummy underneath. "And n-nickle, uh, ah!" Elsa's lips tickled against the spot just below her ear as the older woman turned her head slightly. "N-neodymium!"

"Hmm?" Elsa hummed, air escaping from her parted lips and brushing over Anna's neck.

"E-Elsaaaaa," she whined, scooching away and turning to face her sister. "Y-you're too close-" Anna's eyes widened to an impossible degree when she caught sight of Elsa's pale body, arms tangled together at head height, back arched, breasts - she gulped - on prominent display. Anna's gaze lowered and then shot back up when she saw that Elsa's legs were spread wide. Her eyelids squeezed shut as her thoughts grasped at the song she'd been singing, trying to remember the order of the elements, but all she could think about was how soft Elsa's skin looked, how much she wanted to just reach out and -

Apparently her hand was of like mind; Anna flinched when she felt pliant flesh under her palm and her eyes shot open to glare at the offending appendage as it stroked Elsa's toned abdomen. The touch didn't rouse Elsa from her slumber, and Anna couldn't bring herself to take her hand away from her sister. She traced shapes over Elsa's somewhat defined abs, dipping into the blonde woman's belly button for a moment, the fine hairs, almost invisibly blonde, tickling the pads of her fingers.

Anna's eyes flickered up to Elsa's face with the older woman let out a soft sigh, but she was still asleep. Her expression was so peaceful and slack, her mouth slightly open, her lips wet with saliva.

Anna froze, her stare zeroing in and her sister's plush, moist lips. She couldn't lie to herself — she wanted to kiss them. Suck on them. Nibble them, before moving lower on Elsa's body. Groaning, Anna rolled over again, facing away from her sister and wriggling uncomfortably to adjust the slight tightness of her pajama pants. She pulled up her shirt to just under her breasts before pulling the waistband away from her hips and reached inside to untangle her panties from her hard cock, hand engulfing it fully. Her hand stroked it once — twice — three times before she stopped herself.

She couldn't masturbate in her sister's bed. No matter how much she wanted to. Despite being a bit less endowed than the average person (and Kristoff didn't count — they'd compared sizes once and honestly she'd be surprised if he ever found someone that could take the whole thing at once. Seriously, she swore it was literally the size of her forearm) she made quite a mess when she came.

You don't have to come, an insidious and tempting voice that, strangely enough, sounded like her friend Olaf, bubbled up in her brain. Just stop right before and it'll be alright.

Before she could decide whether or not to agree with the little Olaf on her shoulder, Elsa cuddled into her back again, arm reaching around and hand landing on the arm Anna was currently holding her cock with. It jumped against her palm and she squeezed automatically, a hushed groan breezing through her lips. Elsa wrapped her hand around Anna's and threaded their fingers together, something they did often while awake, although Anna had never been caressing her dick at the time.

She had no idea what to do. She tried to release her cock, but as soon as she let go Elsa squeezed her hand back around it, the pads of her older sister's hands brushing against the sensitive skin of her shaft and head. Anna let out a choked gasp and bucked her hips, accidentally grinding her ass against Elsa's pelvis when she pushed back and thrust forward again.

"So cute…" Elsa's sleepy words came out more like a sigh than anything else, and Anna froze, eyes widening. When the older girl didn't move or say anything else, Anna realized she was still asleep. She quickly pulled away from her dick, causing their hands to disconnect and Elsa's to land on her belly with a sharp slap, her nails digging in slightly. Anna swallowed a whimper and her cock jumped and throbbed. Elsa's hand flattened out over Anna's stomach, revealing little half moons impressed into Anna's skin.

Fuck. Precum was leaking from her slit already. She tried to take deep, calming breaths and close her eyes, shutting out the sensation of Elsa's palm against her belly. Her exhaustion fought the heat in her crotch, making it a bit easier for her to ignore her hardness and therefore make herself go a bit softer. The fact that she was in bed with her sexy, naked older sister who was currently touching just above where her dick jutted out of her body kept her from going completely flaccid, but she calmed herself down enough to drift off slightly, listening to the howling winds still raging outside.

She jerked awake again when she felt strong, sure, quick strokes along her length, quickly building her towards an explosive orgasm she felt boiling in her balls. Honestly, it wouldn't have taken much anyway, given the fact that Anna's watchful roommate had kept her from coming for, like, the past two months since she had last been home. But Elsa's hand was soft yet firm and the way she jerked Anna's cock was better than any hand Anna had ever felt. Anna was sure she was going to spurt all over Elsa's bed in about two seconds.

But one second later, Elsa stopped.

"No," Anna whined, trying to reinstate the delicious friction by humping into the hole that Elsa's hand had created. The fist had gone slack, however, and began trailing up Anna's stomach to snuggle her closer to Elsa, who had begun to snore lightly. "Elsa, please." Dick leaking enough pre to soak the lap of Anna's pajama pants, Anna bit her lip and took in a slow, steadying breath. She needed to calm down. This had already gone far enough. She had more control than this. She had morals. She had integrity.

She really, really had to pee.

Escaping Elsa's hold with some difficulty — and tearing her eyes away from Elsa's naked form with even more difficulty — Anna rolled out of the bed and shuffled into Elsa's private bathroom, erection bobbing cheerfully in her pants. It was still freezing, and Anna regretted not wearing socks to bed. She nearly yelped when she stepped onto the linoleum floor with her bare feet, not bothering to close the door so she could make a quick escape back into the warmth of Elsa's bed.

As she pulled down her pajama pants and boxers, Anna's dick flew up and slapped her lower belly, still dripping, but not as much as earlier. It pulsed hotly when she grabbed it to aim it down into the toilet bowl, careful to not get piss on her hands as she relaxed her bladder and let it fly. Her swollen erection began to subside and she sighed with relief to the sound of her urine hitting porcelain.

After cleaning up, flushing, and discarding her soaked pants into the hamper, Anna quickly hopped back into bed, shivering in her t-shirt and boxers and avoiding looking at Elsa, who seemed to be still fast asleep. Anna's cock barely made a bulge in her underwear now that it wasn't hard anymore, but when Elsa's arm wrapped around Anna again she could see it twitch against the fabric before settling. She let herself enjoy the warmth of her older sister snuggling against her back and closed her eyes, breathing in the cold but pleasant scent of her sister's room.

Elsa giggled and Anna froze, wondering if the blonde was still sleep talking. "So little… baby sister…" Anna wasn't sure what Elsa was dreaming about, but she couldn't help but feel self conscious about how little she actually was — and not just in regards to her petite bone structure. She wasn't quite four inches at her most erect, and was actually pretty thick despite her lack of length, but she still felt small, especially when her dick practically disappeared when she wrapped her hand around it. Flaccid she was about two. She didn't spend much time standing naked in front of a mirror, that was for sure.

Another giggle came from behind her and Anna sighed, knowing she shouldn't even be worrying about sort of thing, especially with her big sister sleeping beside her. Luckily — or unluckily, depending on your point of view — those thoughts flew straight out of Anna's head when she felt Elsa's hips start rolling against Anna's backside.

She was grinding on Anna's ass.

What.

Soft sighs and mewls escaped her lips to brush over the back of Anna's neck and made the redhead shiver, the trembling intensifying when Elsa's hand rested on her thigh again. The grinding grew rougher and Anna felt the lap of her boxers grow slightly wet as Elsa threw her leg over Anna's hips and slipped her hand down to grab Anna's dick once more. Anna could only barely bring herself to stop her older sister's movements; it felt too good, and half of her brain was begging to let things finish.

The other half won out, and Anna rolled away from Elsa's body, her face sweating and red as she shook Elsa's shoulder vigorously. Her sister wrinkled her nose and blinked open her eyes, staring blearily at Anna for a moment before sitting up slightly. "Anna? Is something wrong?" Elsa's gaze flitted over Anna in a way that made the younger sister feel like she was the naked one, but Anna shook off the feeling.

"Uh, um, not exactly… It was just that you," Anna stuttered over her explanation, sure that it probably wasn't a good idea to tell Elsa exactly what had been going on, "you were, er— talking in your sleep! Yeah! And I got worried, because you sounded—," Horny, "Er, upset."

Elsa smiled bashfully and pulled the blankets further over herself, tucking a stray hair behind her ear. "Don't worry, Anna. That happens when I sleep on my right side — it's been like that since I was little. Here," Elsa rolled over, baring her back and butt to Anna as she lifted the covers. Anna gulped. "Snuggle up to me and I'll try not to keep you awake any longer. I don't want you to get cold."

Anna bit her lip, her heart beating hard in her chest and her dick twitching with the rhythm. She was as hard as steel, and she knew if she cuddled up to her sister's backside she'd definitely feel it against her naked ass.

"Come on, now I'm getting cold," Elsa teased, prompting Anna to grit her teeth and sidle up behind Elsa.

"Like it bothers you," Anna groused. Elsa's only response was a quiet grunt, and just like that her breathing slowed and she was back asleep. Anna had always envied that ability. As it was, snuggling with Elsa was pretty comfortable, and very warm, so she tried to relax and enjoy the feeling of her older sister's body pressed against her own.

Her eyes closed, her breathing slowed, and she could feel herself drifting off again when she felt a movement. A tiny movement that she attributed to Elsa shifting in her sleep until it happened again. Elsa's backside rolled slightly, brushing against Anna's still straining erection. Something soft caressed Anna's head and she nearly yelped before she realized her cock had slipped out of her boxers and between Elsa's round cheeks.

The tip of her dick was resting against Elsa's lips.

Anna inhaled sharply and let out a whine when Elsa's hips rolled again, causing Anna's head to slip just inside of Elsa's slit. Anna sucked in air so fast it whistled, jerking her hips and burying half of her cock inside of Elsa in one solid thrust. Elsa grunted and Anna froze, frightened, but after a minute the older girl didn't seem to stir. Pulling out as slowly as she could, trying not to groan as Elsa's walls grasped at Anna's retreating cock, Anna nearly made it out before Elsa backed up against Anna and forced her dick back inside again in a slow movement.

Elsa sighed contentedly and Anna restrained herself from screaming. She should not be doing this. They should not be doing this. This was wrong, but oh God did it feel right. Especially when Anna could feel how wet Elsa was around her cock, as it was buried about three quarters of the way inside of Elsa and being squeezed pleasantly.

Anna began to rock her hips very slowly, checking with each motion that Elsa was still asleep, her long lashes resting against her pale cheeks and her mouth slightly open, releasing measured breaths. Every one of Anna's thrusts was met with a squeeze of her dick, and Anna kept them slow and even. All too quickly her cock was all the way inside, and although she wished she could go deeper, Anna knew she couldn't, just as she knew she couldn't grab her sister's hips and slam in and out of her. As much as she wanted to.

She took a chance and cupped Elsa's waist with a gentle hand, her eyes watching Elsa's face intently for any signs of pain or discomfort or waking up. When Elsa's expression didn't change, Anna strained her hips upward, closing her eyes when she felt Elsa's insides massage along her shaft. Something inside of her was building up, and she knew it was almost time for her to come, but Anna didn't want to stop. It had been far too long since Anna had even masturbated, let alone had sex. She continued to move her hips, her slow thrusts growing a little more sporadic. Her breaths came in shaking rasps as her front pressed against Elsa's back, their torsos moving in time together as Anna pressed her face into Elsa's neck.

Suddenly, every muscle in her body seemed to tighten, starting from the heels of her feet and traveling up to her neck and shoulders. Her grasp on Elsa's waist shook and she could feel herself twitch inside of her big sister.

And then, she started to come. She felt her sperm travel through her cock and spurt into Elsa's cunt, a huge load of it, coating her core hot and fast. To Anna's surprise, another glob shot out of her and into Elsa, just as big as the first. She squeezed her eyes even harder, trying to keep quiet and still as she pumped load after load from her cock, a rush of heat from her thrumming balls sparking all the way to her throat and back. Her cream filled up Elsa's pussy and oozed out from between Elsa's lips, dripping thick and boiling onto her thighs and ass cheeks as well as back onto Anna's dick.

When it finally stopped, Anna lay panting behind Elsa, her dick slipping out of Elsa's slick cunt. She felt her body rest upon the sheets, heavy and tired, yet satisfied and content. Her sweat made the clothing on her skin uncomfortable, but still, it all felt amazing. She looked down to see the mess she made, nearly impossible amounts of cum covering Elsa's center, thighs, and ass, as well as the sheets on the bed. There was no way Elsa wouldn't know what happened when she woke up; Anna had no way of clean up after herself. Her face flamed, but part of her felt pleased, even a little bit daring about facing Elsa after her older sister realized what had gone on.

Anna smiled and felt her cock twitch as she pulled Elsa closer to her and nuzzled her neck. Maybe they'd keep each other warm tomorrow night, too.


End file.
